1. Field of the invention
The present invention concerns a rational installation for manufacturing charcoal coupled to a system for eliminating fumes by incineration-aspiration and washing, and a manufacturing method using an installation of this kind.
The invention is also directed to using a single installation for successively carbonizing and drying the wood and discharging the charcoal manufactured.
2. Description of the prior art
The relatively small number of carbonization sites on which the wood is pre-dried are obliged to carry out lengthy and numerous handling operations using powerful and costly forklift trucks.
The applicants have discovered that it is possible to reduce the number of furnaces by one third and that it is sufficient to use a small conventional forklift truck instead of the extremely powerful forklift trucks previously needed to move the heavy filled furnaces.
There is a proportionate saving in labor, not to mention the elimination of time wasted in unnecessary handling operations.
One modern technique used to carbonize wood without pollution is to burn the gas resulting from carbonization in an incinerator.
The present invention makes it possible to capitalize on the cost-free heat energy produced by burning this gas for ancillary purposes, such as heating, and also, and most importantly, direct use of this heat energy to dry the wood before it is converted into charcoal in the same furnace, without any handling operations and merely by the manipulation of two valves.
The moisture content of the wood has a significant effect on the carbonization, the ideal wood for carbonization being anhydrous.
In practise, carbonization is possible with moisture contents up to 25 or 30%, but with these moisture contents a significant quantity of wood is necessarily burnt to eliminate the water from the remainder, and therefore wasted.
The total carbonization time is easily doubled in this case.
This wastage in terms of materials and time is naturally increased when the moisture content is even higher.
It is therefore imperative to dry the wood.
Natural drying as used until now required storage for at least one year if the geographical situation of the site was good, a large surface area, and good exposure to the sun and wind.
Consequently, the size of the investment tied up in this way was considerable.
A method for drying the wood without costly input of heat energy should therefore significantly reduce operating overheads through savings in time and raw materials to make the installation more profitable.
One object of the invention is therefore a device for manufacturing charcoal enabling harmful fumes to be eliminated and capitalizing on the heat energy produced in this way.
Another object of the invention is a method of manufacturing charcoal using a device of this kind.